Avionaut MaxSpace – European Booster Seat

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Avionaut MaxSpace in bright, beautiful red!

When we heard about the Avionaut MaxSpace, having already seen their amazingly light infant seat, the Pixel, and their 25 kg rear facing seat, the Sky, we had to see what they could do with a booster. Luckily they were happy to provide us with two beautifully sleek boosters for us to try out!

CSFTL Quick Stats

  • Weight range: There are no weight limits for the seat; while early models had a 36 kg weight limit indicated on the sticker and in the manual, Avionaut tells us that 36 kg is only a guideline and not a hard limit. New production seats will not have a weight limit.
  • Height range: overall height of 100-150 cm
  • Lowest belt guide position: 38 cm
  • Highest belt guide position: 58 cm
  • Avionaut recommends a maximum of 10 years of use
  • Avionaut recommends that you replace the seat after any crash. Should you meet their requirements they may offer to replace your seat free of charge.


  • Width at widest point on base (front of the seat pan): 32 cm
  • Width at narrowest point on base (at the front): 22 cm
  • Width at widest point of seat: 43 cm
  • Shoulder area measurement: 33 cm when seat is at its lowest position
  • Seating area width (at the back): 25 cm
  • Seat pan depth: 35 cm
  • Weight of booster: 8 kg


  • Repositionable side impact block
  • R129 certified
  • Eye-line marker on headrest
  • ISOFIX installation
  • Recline setting


The MaxSpace is available in four beautiful colors, two of which we got to try out with our models.

The removable soft goods can all be machine washed at 30 on a gentle cycle and line dried. All other parts of the seat may be washed with soap and water. The manual includes easy-to-understand pictorial instructions for removing the cover, allowing you to follow them in reverse to replace the cover after a good wash.

R129 vs. i-Size

R129 are the latest car seat regulations in Europe. These regulations have made a number of changes for car seats, but the most important changes for boosters are that boosters are not required to have weight limits (manufacturers may still choose to set weight limits, however), and side impact testing is now required and regulated.

Many consumers mistakenly believe that all R129 seats are i-Size certified, but that isn’t the case. Rather, i-Size is one part of the larger R129 regulations. In this case, the MaxSpace is R129 certified, but is not i-Size certified. This means only that the MaxSpace does not fit inside the “imaginary box” designated by the i-Size parts of the regulations, and so is not guaranteed to fit in all i-Size compatible vehicles. It is, however, roomier and taller for bigger kids, and it is still required to pass all of the testing regulations required under R129.

Height Adjustment

Squeeze the handle, then push or pull while holding to slide the headrest to the correct position.

To adjust the height of the seat, squeeze the handle at the back of the headrest, and position the headrest at the correct height.

Handy eye-line marker on the Avionaut MaxSpace

Where to position your child’s headrest isn’t going to be much of a guessing game with this seat due to its eye-line marker on the left of the headrest. Simply pop your child in the seat and adjust the headrest using the handle on the back until the embroidered line lines up with the middle of your child’s eyes. This handy eye-line marker should help ensure the headrest is ideally placed for correct fit of the vehicle shoulder belt.

The maximum height of the MaxSpace is taller than any other European booster we have tried so far. This is fantastic for tall kids, and coupled with the lack of a weight limit means it should last most kids until they no longer need a booster. What a fabulous combination – incredible height AND no weight limit! Of course, as with any booster, the shape and size of your vehicle may mean the MaxSpace can’t be extended to its full height.

Side Impact Block

The side impact block on the MaxSpace is not the easiest to attach at first.

The MaxSpace comes with a side impact block to help absorb the energy of a side impact crash. This MUST be installed on the seat on the side closest to the vehicle door. Both of our test families found that this block wasn’t the easiest to install – they both resorted to using a flat-head screwdriver to gently lever the block into place. Avionaut suggests that placing the block at the top of the plastic shell, then sliding it down into position and slightly lifting the tab for it to click into place is the best strategy. Luckily, after the first go it does become easier – our second test family was able to move it to the other side without much difficulty at all.

Belt Guides

The shoulder belt on the MaxSpace occasionally slips out of the guide.

The seat belt guides on the MaxSpace are green (in line with R129 regulations) and are very obvious, hopefully helping to reduce misuse. We did find that the shoulder belt had a bad habit of coming out of the belt guide in some seating positions. We reached out to Avionaut and they told us they’re aware of the problem and are working on a small fix to prevent the issue from happening in the future.

Proper seat belt routing on the Avionaut MaxSpace

Proper seat belt routing on the Avionaut MaxSpace

Both the lap and shoulder belt must be routed under the armrest on the buckle side; on the other side only the lap belt should be under the armrest.

Installation: With ISOFIX

Getting the side impact block on the first time is not the easiest, but it does get easier with time!

The first step (and the most difficult!) is to install the side impact block onto the side of the seat closest to the vehicle door. Slide the ledge on the fat side of the block into the designated gap between the shell and the cover, then click the tab on the block into place – you’ll need a bit of oomph to get it on there.

Push the lever down and pull the ISOFIX arms out at the back of the seat.

Once the impact block is installed, slide out the two ISOFIX arms by squeezing one of the levers placed at the sides of the front of the seat.

The indicators on the ISOFIX arms turn green when correctly attached.

Line up the arms with the ISOFIX anchors in your vehicle and push them on. You’ll hear a click and the indicators on the arms will turn green. Then push the seat back so that it is flush with the vehicle seat.

Now slide the shoulder section of the adult seat belt through the small gap and into the green belt guide and you’re done!

Installation: Without ISOFIX

The MaxSpace can also be used without ISOFIX. While this option is not shown in the manual, Avionaut tells us that they already have approval for use without ISOFIX, and it will be shown in updated manuals.

Using the MaxSpace without ISOFIX is as simple as placing it on the seat.

To install without ISOFIX, simply leave the ISOFIX arms stored on the seat and place the booster on the vehicle seat. Push it back so it’s flush with the vehicle backrest. Thread the shoulder belt through the green shoulder belt guide, and you’re good to go! Do remember to buckle the booster up when it’s not occupied so it doesn’t become a projectile during a crash.

Due to the seat’s weight, we’d strongly recommend using ISOFIX whenever possible.


Squeeze the handle on the front bottom of the seat, then pull forward to recline the MaxSpace.

Unlike many boosters, the MaxSpace offers your child the option to recline. To recline the seat, squeeze the lever at the front middle of the seat when it’s unoccupied, then pull the seat forward. The back will tilt back slightly. The amount of recline doesn’t seem huge, but our 8 year old model says it makes a big difference and that he absolutely loves the recline setting!

Fit to Child

7 Years Old

7 Year Old in the Avionaut MaxSpace

7 Year Old in the Avionaut MaxSpace

Our 7 year old booster rider is 29kg and 130cm tall. He’s ridden in many a booster and has loved using this seat, even requesting for it to remain in the car as his regular seat. He has never had any issues buckling the seat in and loves the angle of the headrest.

His belt fit is great in this seat with the lap belt low over his pelvis and shoulder belt beautifully positioned over his collarbone. Unfortunately we have had to reinsert the belt into the guide a few times since getting this seat as it has a habit of sliding out in our car.

Sadly due to current conditions there have been no long haul rides for him to try out the recline feature for a nap.

8 Years Old

8 Year Old in the Avionaut MaxSpace

8 Year Old in the Avionaut MaxSpace

Our 8-year-old rider is on the smaller side of the growth charts. He weighs 24.4 kg and is 123 cm tall. He gets a fabulous fit in the MaxSpace, and he loves the seat. He’s a veteran booster rider (and reviewer) and he strongly prefers the MaxSpace. He loves the recline setting, saying he can “finally chill out” in the car. He’s also thrilled with the red cover and finds the seat very soft and comfortable. We haven’t had any issues with the seat belt coming out of the belt guide, and he’s able to easily buckle the seat on his own. We do need to remind him to put the shoulder belt under the buckle side armrest, but with a little time that should become second nature to him.

9 Years Old

Avionaut MaxSpace 9 year old fit

Avionaut MaxSpace 9 year old fit

Our 9-year-old booster rider weighs 32.8kg and is 140cm tall. While she loves the seat pan (it’s her favorite by far) she does feel restricted in her shoulders and finds the headrest too close to her head (she is a rather opinionated child). Her belt fit, as with her brother, is great – nice and low on her hips and centered over her collarbone.

12 Years Old

12 year old in the Avionaut MaxSpace

At 149 cm, our last booster rider is testing the seat nearly to its limits. He loves the seat and finds it very comfortable – he’s asked to keep using it! He has no complaints about feeling constricted and found the headrest very comfortable.

As you can see, he still has a great belt fit, though we did find that the seat belt popped out of the guide more easily than with our younger riders. Amazingly, we still have one more height adjustment on the seat before it is outgrown.

Important Information: Where to Find

Expiration: Avionaut recommends that this seat not be used for longer than 10 years; this information is located in the manual.

Manual storage: Unfortunately we have been unable to locate a manual storage location on this seat. There’s a cutout area on the bottom of the base of the seat, but the manual doesn’t fit in there. We would love to see this feature added so that the manual can stay with the seat for ease of reference for caregivers.

Airline Approval: The MaxSpace is not airline approved. Due to its weight and solid construction we would not recommend it for use while traveling.

Overall Thoughts

The Avionaut MaxSpace is a sturdy, long lasting booster with the added benefit of not having a hard weight limit. It should last the vast majority of children until they no longer need a booster, which is a big plus. Most kids find it comfy, and the recline position plus the supportive headrest can help keep even sleepy riders in a safe position.